net: tc35815: Drop unused variable

Commit e7f4dc35 ("mdio: Move allocation of interrupts into core")
removes some code from tc_mii_init(), but does not remove a now unused
variable. This results in the following build warning.

drivers/net/ethernet/toshiba/tc35815.c: In function 'tc_mii_init':
drivers/net/ethernet/toshiba/tc35815.c:670:6: warning: unused variable 'i'

Fixes: e7f4dc35

 ("mdio: Move allocation of interrupts into core")
Cc: Andrew Lunn <andrew@lunn.ch>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>